MicrosoftFirst, you don't have to uninstall Office 666 (sorry, 365!), run a macro, or run the registry hack to get rid of Modern Comments. You can turn off automatic updates and then roll back to a classic comments version (pre-March 2021 at a guess). This somewhat defeats the object of the subscription model, but it seems to work for a lot of people. But it's not a long-term option.
To find out how to roll back your current Office 365 build, Google "roll back office 365 build" and look at the zendesk.com method or the IT Tech Tips versions that should appear on the search results first page. Essentially identical, but I think more user friendly than the MS one that appears on that same page.
If you decide that a perpetual licence version is the route to go, then in most instances you won't be able to run a perpetual licence of Word/Office alongside Office 365, so you will have to uninstall the latter first. You won't lose any docs by uninstalling and reinstalling to an older version of Word/Office. What you will lose are any user-defined macros or keyboard shortcuts you've developed and any desired functionality that 365 has over the version you choose to install. But there are ways to keep those macros or keyboard shortcuts that should continue to work in most instances (probably); and you might want to consider this with the roll back option, just in case.
